Applicants are not aware of any prior art reference which, in their respective judgments as one skilled in the prostaglandin art, would anticipate or render obvious the novel compounds of the instant invention; however, for the purpose of fully developing the background of the invention and establishing the state of the requisite art, the following reference is set forth:
U.S. Pat. No. 3,876,690, which discloses certain 11-(2-hydroxyethoxy)-9-keto and 9-hydroxy-prostenoic acid derivatives.